Controlling morphology evolution of AlN nanostructures: influence of growth conditions in physical vapor transport

A series of AlN nanostructures were synthesized by an ultrahigh-temperature, catalyst-free, physical vapor transport (PVT) process. Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) detection show that high quality AlN nanowires were prepared. Nanostructures including nanorings, nanosprings, nanohelices, chain-like nanowires, six-fold symmetric nanostructure and rod-like structure were successfully obtained by controlling the growth duration and temperature. The morphology evolution was attributed to electrostatic polar charge model and the crystalline lattice structure of AlN. (paper)